JP2003034208A - Airbag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airbag which improves efficiency for the full use of gas and enables a major part to be inflated at an early stage even with the small output power of an inflater. SOLUTION: A first chamber 1 is formed by being surrounded by a first inner panel 30 and a font panel 10. A second chamber 2 is located at the outer periphery side of the first inner panel 30 and at the front side of a second inner panel 40. The second chamber 2 is connected to the first chamber 1 through a transmission hole 33. A third chamber 3 is located at the outer peripheral side of the first inner panel 30 and at the rear side of the second inner panel. The third chamber 3 is connected to the second chamber 2 through a transmission hole 42 and to the outside of the airbag through a vent hole 24. The chambers 1, 2 and 3 are inflated in this order when an actuation for a gas blowout of the inflater 18 is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for protecting an occupant in an emergency such as a vehicle collision, and more particularly to an airbag suitable as a driver's seat airbag installed on a steering wheel.

[0002]

2. Description of the Related Art As an airbag device for a driver's seat, an airbag mounted on a retainer and folded and covered with a cover member called a module cover is often used.

When a sensor detects a collision of a vehicle, the inflator is actuated, and the gas (inflation gas) generated from the inflator deploys the airbag.

JP-A-1-247242 and JP-A-5-242242
No. 155300 is an airbag in which the inside of the driver airbag is divided into a central chamber and two chambers on the outer peripheral side by a partition panel, the central chamber is inflated first, and then the outer chamber is inflated. Is listed. The panel for this compartment is provided with a through hole for gas distribution. This partition panel connects the rear side and the front side of the airbag, and has a function of preventing the airbag from protruding forward when inflated.

[0005]

Since the above-mentioned two-chamber type airbag has a relatively large volume as a whole, the airbag must be used as an inflator (gas generator) in order to inflate the outer periphery of the airbag sufficiently quickly. It was necessary to use a large capacity one. That is, the effective utilization of gas is low.

It is an object of the present invention to provide an airbag which can improve the effective utilization of gas and protect an occupant even if a small capacity inflator is adopted.

[0007]

The airbag of the present invention comprises:
In an airbag having an opening for supplying gas at a rear portion and facing an occupant when inflated, the inside of the airbag has a first chamber, a second chamber adjacent to the first chamber, and a second chamber adjacent to the first chamber. The second chamber is divided into at least three chambers adjacent to the third chamber, and the gas is configured to flow from the first chamber through the second chamber to the third chamber. To do.

In such an airbag, gas is supplied into the airbag from an opening or an inflator inserted in the opening, and the airbag is inflated. This gas expands the first chamber first, then the second chamber,
Then, the third chamber is expanded. As a result, the gas is retained in the bag for a longer time than in the conventional example, and the effective gas utilization can be improved.

In this airbag, since the inside of the airbag is divided into at least three chambers and the first, second and third chambers are inflated sequentially, the first chamber is extremely early. And the second chamber also expands relatively early. Therefore, the portion of the airbag occupied by the first chamber and the second chamber is inflated fairly early after the inflator is activated, and most of the airbag can be inflated early. Becomes

In the present invention, the first chamber may be provided so as to reach from the opening to the front portion when the airbag is inflated. In this way, the center portion of the airbag is inflated first. In this case, both the second chamber and the third chamber may surround the outer periphery of the first chamber, and the second chamber may be arranged on the front side of the third chamber. preferable. By doing so, the second chamber expands from the front side of the first chamber, which has expanded very early, to the lateral side, so that the occupant can be received early even on the outer peripheral side of the airbag. Becomes

However, in the present invention, the second chamber may surround the outer periphery of the first chamber and the third chamber may surround the outer periphery of the second chamber. In this case, the second chamber adjacent to the first chamber can be expanded early so as to surround the first chamber.

In the present invention, the first chamber is arranged only along the rear portion of the airbag, and the second chamber and the third chamber are arranged on the front side of the first chamber. May be With this structure, the airbag largely inflates laterally early after the actuation of the inflator, and then inflates toward the occupant.

In this case, it is preferable that the second chamber is arranged at the center of the airbag and the third chamber is arranged at the outer circumference of the second chamber. With this configuration, following the inflation of the first chamber, the second chamber in the center of the airbag is inflated early, and the occupant can be received in the second chamber. The second chamber may be arranged in the center of the airbag and the third chamber may surround the outer periphery of the second chamber. Even in this case,
The first chamber and the second chamber expand relatively early.

In the present invention, a gas introducing portion may be provided which connects the first chamber and the third chamber. By doing so, the expansion of the third chamber can be accelerated.

In the present invention, the chamber into which the gas finally flows may communicate with the outside of the airbag through the vent hole. By providing this vent hole, it is possible to absorb the impact when the occupant collides with the airbag. However, in the present invention, it is also assumed that the occupant bumps into the airbag before the last chamber is completely inflated. In this case, the shock can be absorbed by the gas flowing from the second chamber to the third chamber,
The impact can be sufficiently absorbed without providing a vent hole.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Embodiments will be described below with reference to the drawings. 1 (a) is a longitudinal sectional view of the airbag according to the embodiment when inflated, FIG. 1 (b) is a sectional view taken along the line BB of FIG. 1 (a), and FIG. 2 (a). ) Is an exploded view showing the structure of the airbag, and FIGS. 2B and 2C are sectional views.

The upper half of the airbag of FIG. 1 (a) shows a cross section taken along line A ₁ -A ₁ of FIG. 1 (b), and the lower half of the airbag is A ₂ − of FIG. 1 (b). The cross section along the A ₂ line is shown.

The outer shell of this airbag is constituted by a circular front panel 10 and a circular rear panel 12, respectively. The front panel 10 and the rear panel 12 are made into a bag shape by sewing the outer peripheral edge portions with a suture thread 14. An opening 16 for inserting an inflator 18 is provided in the center of the rear panel 12. A small hole 26 for passing the bolt 22 is provided around the opening 16, and the edge of the opening 16 is fastened to the bolt 22 and the bolt 22 between the holding ring 20 and the flange 18a of the inflator 18. It is clamped by a nut (not shown). A vent hole 24 is provided in the rear panel 12.

The inside of the airbag is formed by the first inner panel 30 and the second inner panel 40,
It is divided into a second chamber 2 and a third chamber 3. The first inner panel 30 has an opening 31 at the center into which the inflator 18 is inserted and a small hole 32 around which the bolt 22 is inserted. The first inner panel 30 is provided with four through holes 33 for gas circulation. The number of through holes 33 is not limited.

The inner peripheral edge of the first inner panel 30 is sandwiched between the flange 18a of the inflator 18 and the pressing ring 20. The outer peripheral edge of the first inner panel 30 is sewn to the front panel 10 with a suture thread 34.

A proximal end side of an ear piece 36 is sewn to the first inner panel 30 with a suture thread 37. Two ear pieces 36 are provided, but the number is not limited. The ear piece 36 is provided at a position between the through holes 33 or in the vicinity thereof.

The second inner panel 40 has an opening 41 in the center and a through hole 42 for gas passage near the middle in the radial direction. Two tabs 43 extend from the inner periphery of the opening 41 toward the center of the opening 41. This tab 43 is preferably integral with the second inner panel 40. The tab 43 is sewn to the tip side of the ear piece 36 by a suture thread 44.

The first inner panel 3 is provided on the front panel 10.
The outer peripheral edge portion of No. 0 is sewn with the suture thread 34, and the outer peripheral edge portion of the second inner panel 40 is sewn with the suture thread 45 to the rear panel 12. Then, the ear pieces 36 of the first inner panel 30 and the tabs 43 of the second inner panel 40 are sewn together, and then the outer peripheral edge portions of the front panel 10 and the rear panel 12 are sewn to obtain the state of FIG. 2 (b). Become.

Thereafter, as shown in FIGS. 1 and 2 (c), the central opening 31 of the first inner panel 30 is coaxially overlapped with the opening 16 of the rear panel 12, and the holding ring 20 and the inflator 18 are attached via the bolts 22. The edge portions of the openings 16 and 31 are sandwiched between the flange 18a (not shown in FIG. 2C). Although not shown, the edge of the inflator mounting hole of the retainer for mounting the airbag is also sandwiched between the pressing ring 20 and the flange 18a.

First inner panel 30 and front panel 1
The first chamber 1 is formed by being surrounded by 0 and. The tip side of the inflator 18 is inserted into the first chamber 1 through the openings 16 and 31. First room 1
Extends from the rear center of the airbag to the front center.

On the outer peripheral side of the first inner panel 30,
The front side of the second inner panel 40 is the second chamber 2. The second chamber 2 communicates with the first chamber 1 through the opening 33.

A third chamber 3 is formed on the outer peripheral side of the first inner panel 30 and on the rear side of the second inner panel. The third chamber 3 communicates with the second chamber 2 through the through hole 42 and communicates with the outside of the airbag through the vent hole 24.

When the inflator 18 starts the gas ejection operation, the gas inflates the first chamber 1 first. This gas then enters the second chamber 2 through the through hole 33 and
Inflates chamber 2 and then through third opening 42 to the third chamber 3
Enter and inflate it.

As described above, when the inflator 18 is actuated, the first chamber 1 in the center of the airbag is inflated at an early stage, and then the second chamber 2 is moved laterally from the front surface side of the first chamber 1 (all radial directions). ) Expands. Therefore, the radial expansion of the airbag is performed early by the first and second chambers 1 and 2. Since the total volume of the first and second chambers 1 and 2 is smaller than the total volume of the inside of the airbag, even if the output of the inflator 18 is small, the first and second chambers 1 and 2 are sufficient. Inflate early. Since the first inner panel 30 is constructed so as to be installed between the front panel 10 and the pressing ring 20, the airbag is forward (in the occupant direction) at the initial stage of inflation.
It does not stick out too large.

In FIGS. 1 and 2, the front panel 10 is shown.
Although the seam allowance between the rear panel 12 and the rear panel 12 projects outside the airbag, the seam allowance may be arranged inside the airbag as shown in FIG.

In this case, the front panel 10 sewn with the first inner panel 30 and the rear panel 12 sewn with the second inner panel 40 are concentrically aligned, and the outer peripheral edge portions are sewn together. The airbag is then inverted through the opening 16. After that, the ear piece 36 and the tab 43 are opened 1
Pull out from 6 and suture. As a result, the airbag having the structure shown in FIG. 3 is obtained.

When an occupant plunges into the airbag shown in FIGS. 1 to 3, the gas flows out from the vent hole 24 to absorb the shock. However, when the size of each panel, the size of the through hole, the stitching position, or the output of the inflator 18 is designed or selected so that the occupant thrusts into the airbag before the third chamber 3 is completely inflated, The vent hole may be omitted. In this case, the second
The shock is absorbed by the gas flowing from the chamber 2 to the third chamber 3.

In the present invention, the through hole 42 of the second inner panel 40 may not be provided. In this case, the gas flows from the second chamber 2 to the third chamber 3 through the space between the inner periphery of the opening 41 of the second inner panel 40 and the first inner panel 30.

In the present invention, as shown in FIG. 4, the first inner panel 30 may be provided with a through hole 50 for directly communicating the first chamber 1 and the third chamber 3 with each other. If you do this,
The expansion of the third chamber 3 also becomes faster.

The airbag shown in FIG. 5 does not allow the first inner panel 30 to communicate with the holding ring 20, but the first inner panel 30 is separated from the rear panel 12. In this airbag, a first chamber 1 is arranged on the rear side of the airbag along the rear panel 12, and a second chamber 2 is arranged on the front side of the airbag along the center of the front panel 10.
Is provided, and the third chamber 3 is provided on the front side of the first chamber 1 along the outer peripheral area of the front panel. A through hole 42 that connects the second chamber 2 and the third chamber 3 is provided in the first inner panel 30. No opening is provided in the second inner panel 40. Other configurations are the same as the first and second
Similar to the figure, the same reference numerals indicate the same parts.

In the airbag of FIG. 5, when the inflator 18 starts to operate, first the first chamber 1 on the rear side of the airbag inflates early, and then the center of the front side of the airbag. The second chamber 2 inflates, and finally the third chamber 3 in the outer peripheral region on the front side of the airbag inflates. Also in this case, since the first and second chambers are inflated early, the inflator 18
It is possible to inflate the airbag so as to catch the occupant early even if the output of the airbag is small.

In FIG. 5, the first chamber 1 and the second chamber 2 are divided by the inner peripheral side of the first inner panel 30 and the second inner panel 30 is provided with a second inner portion in the radial direction. The inner peripheral side of the panel 40 communicates with each other, but conversely, the inner peripheral end of the second inner panel 40 is extended to the center side of the airbag so that the second inner panel 40 allows the first chamber 1 and the second chamber 1 to communicate with each other. Room 2
And may be partitioned. In this case, the inner peripheral end of the first inner panel is connected to the radial middle portion of the second inner panel.

In FIG. 6, the second inner panel 60 is arranged outside the first inner panel 30, and is installed between the holding ring 20 and the front panel 10. The second inner panel 60 is provided with a through hole 61 that connects the second chamber 2 and the third chamber 3 to each other. The inner side of the first inner panel 30 is the first chamber 1, the outer side thereof is surrounded by the second chamber 2, and the outer side thereof is surrounded by the third chamber 3. Other configurations in FIG. 6 are the same as those in FIGS. 1 and 2, and the same reference numerals indicate the same parts.

Also in this airbag, when the inflator 18 starts to operate, the first and second chambers 1 and 2 are inflated early.

The above embodiments are all examples of the present invention, and the present invention can take various forms other than those shown in the drawings. For example, although three chambers are provided in the above embodiment,
There may be four or more chambers.

Further, in the above-described embodiment, the airbag has a point-symmetrical structure substantially in the circumferential direction with the center point of the opening 16 as a point of symmetry, but the present invention is not limited to this. For example, the outer shape of the airbag may be rectangular or polygonal. Further, for example, the second or third chamber may be arranged only in a part in the circumferential direction. Although suturing with a thread is adopted as the joining means in the above embodiment, an adhesive may be used. The present invention can also be applied to airbags other than those for the driver's seat.

[0042]

As described above, according to the present invention, there is provided an airbag in which the main portion of the inflator is inflated early even if the output of the inflator is small.

[Brief description of drawings]

FIG. 1A is a longitudinal sectional view of an airbag according to an embodiment when inflated, and FIG. 1B is a sectional view taken along line BB in FIG. 1A.

FIG. 2 (a) is an exploded view showing the structure of this airbag,
(B), (c) is sectional drawing.

FIG. 3 is a cross-sectional view of an airbag according to another embodiment.

FIG. 4 is a sectional view of an airbag according to another embodiment.

FIG. 5 is a cross-sectional view of an airbag according to another embodiment.

FIG. 6 is a cross-sectional view of an airbag according to another embodiment.

[Explanation of symbols]

1st room 2 Second room 3 Second room 10 Front panel 12 Rear panel 18 inflator 24 Bent hole 30 1st inner panel 33 through mouth 36 ear pieces 40 Second Inner Panel 42 through mouth 43 tabs 60 Second Inner Panel 61 through mouth

Claims (9)

[Claims] 1. An airbag having an opening for supplying gas at a rear portion and facing an occupant when inflated, wherein the inside of the airbag is a first chamber and a second chamber adjacent to the first chamber. And at least three chambers adjacent to the second chamber, the gas is configured to flow from the first chamber through the second chamber to the third chamber. An airbag characterized by being 2. The airbag according to claim 1, wherein the first chamber is provided so as to reach the front portion from the opening in an inflated state. 3. The expansion chamber according to claim 2, wherein the second chamber and the third chamber both surround the outer periphery of the first chamber, and the second chamber is closer to the front side than the third chamber. The airbag is characterized by being arranged in. 4. The expansion chamber according to claim 3, wherein the second chamber surrounds the outer periphery of the first chamber and the third chamber surrounds the outer periphery of the second chamber. Airbag. 5. The inflated state according to claim 1, wherein the first chamber is arranged only along a rear portion of the airbag, and the second chamber and the third chamber are located in front of the first chamber. An airbag characterized by being placed on the side. 6. The airbag according to claim 5, wherein the second chamber is arranged at the center of the airbag in the inflated state, and the third chamber surrounds the outer periphery of the second chamber. 7. The airbag according to claim 1, further comprising a gas introducing portion that connects the first chamber and the third chamber. 8. The airbag according to claim 1, wherein the chamber into which the gas finally flows communicates with the outside of the airbag via a vent hole. 9. The airbag according to claim 1, which has no vent hole.